Hydrogenated oxidized silicon carbon material

ABSTRACT

A low dielectric constant, thermally stable hydrogenated oxidized silicon carbon film which can be used as an interconnect dielectric in IC chips is disclosed. Also disclosed is a method for fabricating a thermally stable hydrogenated oxidized silicon carbon low dielectric constant film utilizing a plasma enhanced chemical vapor deposition technique. Electronic devices containing insulating layers of thermally stable hydrogenated oxidized silicon carbon low dielectric constant materials that are prepared by the method are further disclosed. To enable the fabrication of thermally stable hydrogenated oxidized silicon carbon low dielectric constant film, specific precursor materials having a ring structure are preferred.

This is division of application Ser. No. 09/107,567, filed Jun. 29,1998, now U.S. Pat. No. 6,147,009.

FIELD OF THE INVENTION

The present invention generally relates to a new hydrogenated oxidizedsilicon carbon (SiCOH) low dielectric constant material which isthermally stable to at least 350° C. and a method for fabricating filmsof this material and electronic devices containing such films and moreparticularly, relates to a low dielectric constant, thermally stablehydrogenated oxidized silicon carbon (SiCOH) film for use as anintralevel or interlevel dielectric, cap material, or hard mask/polishstop in a ULSI back-end-of-the-line (BEOL) wiring structure, electronicstructures containing the films and a method for fabrication such filmsand structures.

BACKGROUND OF THE INVENTION

The continuous shrinking in dimensions of electronic devices utilized inULSI circuits in recent years has resulted in increasing the resistanceof the BEOL metalization as well as increasing the capacitance of theintralayer and interlayer. This combined effect increases signal delaysin ULSI electronic devices. In order to improve the switchingperformance of future ULSI circuits, low dielectric constant (k)insulators and particularly those with k significantly lower than thatof silicon oxide are needed to reduce the capacitances. Dielectricmaterials that have low k values have been commercially available, forinstance, one of such materials is polytetrafluoroethylene (PTFE) with ak value of 2.0. However, these dielectric materials are not thermallystable when exposed to temperatures above 300˜350° C. which renders themuseless during integration of these dielectrics in ULSI chips whichrequire a thermal stability of at least 400° C.

The low-k materials that have been considered for applications in ULSIdevices include polymers containing Si, C, O, such as methylsiloxane,methylsesquioxanes, and other organic and inorganic polymers. Forinstance, materials described in a paper “Properties of new lowdielectric constant spin-on silicon oxide based dielectrics” by N.Hacker et al., published in Mat. Res. Soc. Symp. Proc., vol. 476 (1997)p25 appear to satisfy the thermal stability requirement, even thoughsome of these materials propagate cracks easily when reachingthicknesses needed for integration in the interconnect structure whenfilms are prepared by a spin-on technique. Furthermore, the precursormaterials are high cost and prohibitive for use in mass production. Incontrast to this, most of the fabrication steps of VLSI and ULSI chipsare carried out by plasma enhanced chemical or physical vapor depositiontechniques. The ability to fabricate a low-k material by a PECVDtechnique using readily available processing equipment will thussimplify its integration in the manufacturing process and create lesshazardous waste.

It is therefore an object of the present invention to provide a lowdielectric constant material of hydrogenated oxidized silicon carbonwhich is thermally stable to at least 350° C. and exhibits very lowcrack propagation.

It is another object of the present invention to provide a method forfabricating a low dielectric constant and thermally stable hydrogenatedoxidized silicon carbon film.

It is a further object of the present invention to provide a method forfabricating a low dielectric constant, thermally stable hydrogenatedoxidized silicon carbon film from a precursor which contains Si, C, Oand H and which may have a ring structure.

It is another further object of the present invention to provide amethod for fabricating a low dielectric constant, thermally stablehydrogenated oxidized silicon carbon film from a precursor mixture whichcontains atoms of Si, C, O, and H.

It is still another further object of the present invention to provide amethod for fabricating a low dielectric constant, thermally stablehydrogenated oxidized silicon carbon film in a parallel plate plasmaenhanced chemical vapor deposition chamber.

It is yet another object of the present invention to provide a methodfor fabricating a low dielectric constant, thermally stable hydrogenatedoxidized silicon carbon film for use in electronic structures as anintralevel or interlevel dielectric in a BEOL interconnect structure.

It is still another further object of the present invention to provide amethod for fabricating a thermally stable hydrogenated oxidized siliconcarbon film of low dielectric constant capable of surviving a processtemperature of at least 350° C. for four hours.

It is yet another further object of the present invention to provide alow dielectric constant, thermally stable hydrogenated oxidized siliconcarbon film that has low internal stresses and a dielectric constant ofnot higher than 3.6.

It is still another further object of the present invention to providean electronic structure incorporating layers of insulating materials asintralevel or interlevel dielectrics in a BEOL wiring structure in whichat least one of the layers of insulating materials comprise hydrogenatedoxidized silicon carbon films.

It is yet another further object of the present invention to provide anelectronic structure which has layers of hydrogenated oxidized siliconcarbon films as intralevel or interlevel dielectrics in a BEOL wiringstructure which contains at least one dielectric cap layer formed ofdifferent materials for use as a reactive ion etching mask, a polishstop or a diffusion barrier.

It is still another further object of the present invention to providean electronic structure with intralevel or interlevel dielectrics in aBEOL wiring structure which has at least one layer of hydrogenatedoxidized silicon carbon films as reactive ion etching mask, a polishstop or a diffusion barrier.

SUMMARY OF THE INVENTION

In accordance with the present invention, a novel hydrogenated oxidizedsilicon carbon (SiCOH) low dielectric constant material that isthermally stable to at least 350° C. is provided. The present inventionfurther provides a method for fabricating a thermally stable, lowdielectric constant hydrogenated oxidized silicon carbon film byreacting a precursor gas containing atoms of Si, C, O, and H in aparallel plate plasma enhanced chemical vapor deposition chamber. Thepresent invention still further provides an electronic structure thathas layers of insulating materials as intralevel or interleveldielectrics used in a BEOL wiring structure wherein the insulatingmaterial can be a hydrogenated oxidized silicon carbon film.

In a preferred embodiment, a method for fabricating a thermally stablehydrogenated oxidized silicon carbon film can be carried out by theoperating steps of first providing a parallel plate plasma enhancedchemical vapor deposition chamber, positioning an electronic structurein the chamber, flowing a precursor gas containing atoms of Si, C, O,and H into the chamber, depositing a hydrogenated oxidized siliconcarbon film on the substrate, and optionally heat treating the film at atemperature not less than 300° C. for a time period of at least 0.5hour. The method may further include the step of providing a parallelplate reactor which has a conductive area of a substrate chuck betweenabout 300 cm2 and about 700 cm², and a gap between the substrate and atop electrode between about 1 cm and about 10 cm. A RF power is appliedto one of the electrodes at a frequency between about 12 MHZ and about15 MHZ. The substrate may be positioned on the powered electrode or onthe grounded electrode. An optional heat treating step may further beconducted at a temperature not higher than 300° C. for a first timeperiod and then at a temperature not lower than 380° C. for a secondtime period, the second time period is longer than the first timeperiod. The second time period may be at least 10 folds of the firsttime period.

The precursor utilized can be selected from molecules with ringstructures such as 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS, orC₄H₁₆O₄Si₄), tetraethylcyclotetrasiloxane (C₈H₂₄O₄Si₄), ordecamethylcyclopentasiloxane (C₁₀H₃₀O₅Si₅). However, other precursorscomprising Si, C, O, and H containing gases may also be used. Suchprecursors may be selected from the group of methylsilanes, such astetramethylsilane (Si(CH₃)₄) or trimethylsilane (SiH(CH₃)₃)), with orwithout the addition of oxygen to the feed gas. The precursor can bedelivered directly as a gas to the reactor delivered as a liquidvaporized directly within the reactor, or transported by an inertcarrier gas such as helium or argon. The precursor mixture may furthercontain elements such as nitrogen, fluorine or germanium.

The deposition step for the hydrogenated oxidized silicon carbon lowdielectric constant film may further include the steps of setting thesubstrate temperature at between about 25° C. and about 400° C., settingthe RF power density at between about 0.02 W/cm² and about 1.0 W/cm²,setting the precursor flow rate at between about 5 sccm and about 200sccm, setting the chamber pressure at between about 50 mTorr and about 3Torr, and setting a substrate DC bias at between about 0 VDC and about−400 VDC. The deposition process can be conducted in a parallel platetype plasma enhanced chemical vapor deposition chamber.

The present invention is further directed to an electronic structurewhich has layers of insulating materials as intralevel or interleveldielectrics in a BEOL interconnect structure which includes apre-processed semiconducting substrate that has a first region of metalembedded in a first layer of insulating material, a first region ofconductor embedded in a second layer of insulating material whichcomprises SiCOH, said second layer of insulating material being inintimate contact with said first layer of insulating material, saidfirst region of conductor being in electrical communication with saidfirst region of metal, and a second region of conductor being inelectrical communication with said first region of conductor and beingembedded in a third layer of insulating material comprises SiCOH, saidthird layer of insulating material being in intimate contact with saidsecond layer of insulating material. The electronic structure mayfurther include a dielectric cap layer situated in-between the firstlayer of insulating material and the second layer of insulatingmaterial, and may further include a dielectric cap layer situatedin-between the second layer of insulating material and the third layerof insulating material. The electronic structure may further include afirst dielectric cap layer between the second layer of insulatingmaterial and the third layer of insulating material, and a seconddielectric cap layer on top of the third layer of insulating material.

The dielectric cap material can be selected from silicon oxide, siliconnitride, silicon oxinitride, refractory metal silicon nitride with therefractory metal being Ta, Zr, Hf or W, silicon carbide, siliconcarbo-oxide, and their hydrogenated compounds. The first and the seconddielectric cap layer may be selected from the same group of dielectricmaterials. The first layer of insulating material may be silicon oxideor silicon nitride or doped varieties of these materials, such as PSG orBPSG. The electronic structure may further include a diffusion barrierlayer of a dielectric material deposited on at least one of the secondand third layer of insulating material. The electronic structure mayfurther include a dielectric layer on top of the second layer ofinsulating material for use as a RIE hard mask/polish stop layer and adielectric diffusion barrier layer on top of the dielectric RIE hardmask/polish-stop layer. The electronic structure may further include afirst dielectric RIE hard mask/polish-stop layer on top of the secondlayer of insulating material, a first dielectric RIE diffusion barrierlayer on top of the first dielectric polish-stop layer, a seconddielectric RIE hard mask/polish-stop layer on top of the third layer ofinsulating material, and a second dielectric diffusion barrier layer ontop of the second dielectric polish-stop layer. The electronic structuremay further include a dielectric cap layer of same materials asmentioned above between an interlevel dielectric of SiCOH and anintralevel dielectric of SiCOH.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the presentinvention will become apparent from the following detailed descriptionand the appended drawings in which:

FIG. 1 is a cross-sectional view of the present invention parallel platechemical vapor deposition chamber.

FIG. 2 is a graph illustrating a FTIR spectrum obtained on a SiCOH filmprepared by the present invention method.

FIG. 3 is a graph illustrating a FTIR spectrum of a SiCOH film of thepresent invention showing a deconvolution of a Si—O—Si peak into Si—O—Siand Si—O peaks.

FIG. 4 is a graph illustrating the dependence of crack growth velocitydata obtained in water on film thicknesses for the present inventionSiCOH films and typical Si based spin-on dielectric films.

FIG. 5 is a graph illustrating the dielectric constants of the presentinvention SiCOH films prepared under various PECVD processingconditions.

FIG. 6 is an enlarged cross-sectional view of a present inventionelectronic device having an intralevel dielectric layer and aninterlevel dielectric layer of SiCOH.

FIG. 7 is an enlarged, cross-sectional view of the present inventionelectronic structure of FIG. 6 having an additional diffusion barrierdielectric cap layer on top of the SiCOH film.

FIG. 8 is an enlarged, cross-sectional view of the present inventionelectronic structure of FIG. 7 having an additional RIE hard mask/polishstop dielectric cap layer and a dielectric cap diffusion barrier layeron top of the polish-stop layer.

FIG. 9 is an enlarged, cross-sectional view of the present inventionelectronic structure of FIG. 8 having additional RIE hard mask/polishstop dielectric layers on top of the interlevel SiCOH film.

DETAILED DESCRIPTION OF THE PREFERRED AND ALTERNATE EMBODIMENTS

The present invention discloses a novel hydrogenated oxidized siliconcarbon material (SiCOH) comprising Si, C, O and H in a covalently bondednetwork which is thermally stable to at least 350° C. and having adielectric constant of not more than 3.6. The present invention furtherdiscloses a method for fabricating SiCOH films in a parallel plateplasma enhanced chemical vapor deposition chamber. A precursor gascontaining Si, O, C and H and optionally containing molecules which havea ring structure can be used for forming the SiCOH film. The SiCOH lowdielectric constant film can further be heat treated at a temperaturenot less than 300° C. for at least 0.5 hour to improve its thermalstability.

The present invention therefore discloses a method for preparingthermally stable SiCOH films that have low dielectric constant, e.g.,lower than 3.6, which are suitable for integration in a BEOL wiringstructure. The films can be prepared by choosing a suitable precursorand a specific combination of processing parameters as described below.

Referring initially to FIG. 1 wherein a simplified view of a PECVDreactor 10 for processing 200 mm wafers is shown. The gas precursors areintroduced into reactor 10 through the gas distribution plate (GDP) 14,which is separated from the substrate chuck 12 by a gap and are pumpedout through a pumping port 18. The RF power 20 is connected to thesubstrate chuck 12 and transmitted to the substrate 22. For practicalpurposes, all other parts of the reactor are grounded. The substrate 22thus acquires a negative bias, whose value is dependent on the reactorgeometry and plasma parameters. In a different embodiment, the RF power20 can be connected to the GDP 14, which is electrically insulated fromthe chamber, and the substrate chuck 12 is grounded. In anotherembodiment, more than one electrical power supply can be used. Forinstance, two power supplies can operate at the same RF frequency, orone may operate at a low frequency and one at a high frequency. The twopower supplies may be connected both to same electrode or to separateelectrodes. In another embodiment the RF power supply can be pulsed onand off during deposition. Process variables controlled duringdeposition of the low-k films are RF power, precursor mixture and flowrate, pressure in reactor, and substrate temperature. Following areseveral examples of deposition of low-k films from a precursor of TMCTS.In these examples, the precursor vapors were transported into thereactor by using He as a carrier gas. After deposition, the films wereheat treated at 400° C. to stabilize their properties.

EXAMPLE 1

In this implementation example, a plasma was operated in a continuousmode during film deposition. The pressure in the reactor was maintainedat 300 mTorr. The substrate was positioned on the powered electrode towhich a RF power of 25 W was applied at a frequency of 13.56 MHZ. Thesubstrate acquired a self negative bias of −75 VDC. The film thusdeposited had a dielectric constant of k=4.0 in as-deposited condition.After stabilization anneal, the film has a dielectric constant ofk=3.55.

EXAMPLE 2

In this implementation example, the plasma was operated in a continuousmode during film deposition. The pressure in the reactor was maintainedat 400 mTorr. The substrate was positioned on the powered electrode towhich a RF power of 7 W was applied at a frequency of 13.56 MHZ. Thesubstrate acquired a self negative bias of −25 VDC. The film depositedhas a dielectric constant of k=3.33 in as-deposited condition. Afterstabilization anneal, the film has a dielectric constant of k=2.95.

EXAMPLE 3

In this implementation example, the plasma was operated in a pulsed modeduring film deposition, i.e., with a plasma-on time of 18 ms and aplasma-off time of 182 ms per cycle. The pressure in the reactor wasmaintained at 300 mTorr. The substrate was positioned on the poweredelectrode to which a RF power of 9 W was applied at a frequency of 13.56MHZ. The substrate acquired a self negative bias of −9 to 0 VDC. Thefilm thus deposited has a dielectric constant of k=3.4 in as-depositedcondition. After stabilization anneal, the film has a dielectricconstant of k=2.96.

EXAMPLE 4

In this implementation example, a different precursor oftetramethylsilane was used with the plasma operated in continuous modeduring film deposition. The pressure in the reactor was maintained at200 mTorr. The substrate was positioned on the powered electrode towhich a RF power of 9 W was applied at a frequency of 13.56 MHZ. Thesubstrate acquired a self negative bias of −200 VDC. The film thusdeposited has a dielectric constant of k=3.6 in as-deposited condition.After stabilization anneal, the film has a dielectric constant ofk=2.86.

The present invention novel material composition includes atoms of Si,C, O and H. A suitable concentration range can be advantageouslyselected from between about 5 and about 40 atomic percent of Si; betweenabout 5 and about 45 atomic percent of C; between about 0 and about 50atomic percent of O; and between about 10 and about 55 atomic percent ofH. It should be noted that when the atomic percent of O is 0, acomposition of SiCH is produced which has properties similar to that ofSiCOH and therefore, may also be suitably used as a present inventioncomposition. For instance, Example 4 describes a film of SiCH with nooxygen. The SiCH film may be deposited by flowing a precursor gascontaining Si, C and H into a plasma enhanced chemical vapor depositionchamber. The present invention material composition may further includeat least one element such as F, N or Ge while producing similarlydesirable results of the present invention.

The films deposited as described above are characterized by FTIRspectrum similar to the one shown in FIG. 2. The spectrum has absorptionpeaks corresponding to C—H bonds at 2965 cm⁻¹ and 2910 cm⁻¹, Si—H bondsat 2240 cm⁻¹ and 2170 cm⁻¹, Si—C bonds at 1271 cm⁻¹ and Si—O—Si bonds at1030 cm⁻¹. The relative intensities of these peaks can change withchanging deposition conditions. The peak at 1030 cm⁻¹ can bedeconvoluted in two peaks at 1100 cm⁻¹ and 1025 cm⁻¹ as illustrated inFIG. 3. The latter peak is at the same position as in the TMCTSprecursor, indicating some preservation of the precursor ring structurein the deposited film. The ratio of the area of the 100 cm⁻¹ peak tothat of the 1025 cm⁻¹ peak increases from 0.2 to more than 1.1 withdecreasing value of the dielectric constant from 4 to 2.95.

FIG. 4 presents a comparison of the crack growth velocity in water ofthe present SiCOH films with those of low-dielectric constant polymericfilms containing similar elements. The dotted line indicates theresolution limit of the measuring tool. FIG. 5 presents the dielectricconstants of present SiCOH films prepared in different plasmaconditions.

Other gases such as Ar, H₂, and N₂ can be used as carrier gases. If theprecursor has sufficient vapor pressure no carrier gas may be needed. Analternative way to transport a liquid precursor to the plasma reactor isby use of a liquid delivery system. Nitrogen, hydrogen, germanium, orfluorine containing gases can be added to the gas mixture in the reactorif needed to modify the low-k film properties. The SiCOH films may thuscontain atoms such as Ge, N and F.

If required the deposited SiCOH films may further be stabilized beforeundergoing further integration processing to either evaporate theresidual volatile contents and to dimensionally stabilize the films orjust dimensionally stabilize the films. The stabilization process can becarried out in a furnace annealing step at between 300° C. and 400° C.for a time period between about 0.5 and about 4 hours. The stabilizationprocess can also be performed in a rapid thermal annealing process attemperatures above 300° C. The dielectric constant of the SiCOH filmsobtained according to the present invention novel process are not higherthan 3.6. The thermal stability of the SiCOH films obtained according tothe present invention process is up to at least a temperature of 350° C.

The SiCOH films obtained by the present invention process arecharacterized by dielectric constants of k<3.6, and are thermally stablefor process integration in a BEOL interconnect structure which isnormally processed at temperatures of up to 400° C. Furthermore, theseSiCOH films have extremely low crack propagation velocities in water,i.e., below 10⁻⁹ m/s and may even be below 10⁻¹¹ m/s. In contrast,polymeric dielectric films are characterized by crack propagationvelocities in water of 10⁻⁶ m/s to 10⁻³ m/s at similar thicknessesbetween 700 nm and 1300 nm. The present invention novel material andprocess can therefore be easily adapted in producing SiCOH films asintralevel and interlevel dielectrics in BEOL processes for logic andmemory devices.

The electronic devices formed by the present invention novel method areshown in FIGS. 6˜9. It should be noted that the devices shown in FIGS.6˜9 are merely illustration examples of the present invention methodwhile an infinite number of other devices may also be formed by thepresent invention novel method.

In FIG. 6, an electronic device 30 is shown which is built on a siliconsubstrate 32. On top of the silicon substrate 32, an insulating materiallayer 34 is first formed with a first region of metal 36 embeddedtherein. After a CMP process is conducted on the first region of metal36, a hydrogenated oxidized silicon carbon film such as a SiCOH film 38is deposited on top of the first layer of insulating material 34 and thefirst region of metal 36. The first layer of insulating material 34 maybe suitably formed of silicon oxide, silicon nitride, doped varieties ofthese materials, or any other suitable insulating materials. The SiCOHfilm 38 is then patterned in a photolithography process and a conductorlayer 40 is deposited therein. After a CMP process on the firstconductor layer 40 is carried out, a second layer of SiCOH film 44 isdeposited by a plasma enhanced chemical vapor deposition processoverlying the first SiCOH film 38 and the first conductor layer 40. Theconductor layer 40 may be deposited of a metallic material or anonmetallic conductive material. For instance, a metallic material ofaluminum or copper, or a nonmetallic material of nitride or polysilicon.The first conductor 40 is in electrical communication with the firstregion of metal 36.

A second region of conductor 50 is then formed after a photolithographicprocess on second SiCOH film layer 44 is conducted followed by adeposition process for the second conductor material. The second regionof conductor 50 may also be deposited of either a metallic material or anonmetallic material, similar to that used in depositing the firstconductor layer 40. The second region of conductor 50 is in electricalcommunication with the first region of conductor 40 and is embedded inthe second layer of SiCOH insulator 44. The second layer of SiCOH filmis in intimate contact with the first layer of insulating material 38.In this specific example, the first layer of insulating material 38 ofSiCOH is an intralevel dielectric material, while the second layer ofinsulating material, i.e., the SiCOH film 44 is both an intralevel andan interlevel dielectric. Based on the low dielectric constant of theSiCOH film, superior insulating property can be achieved by the firstinsulating layer 38 and the second insulating layer 44.

FIG. 7 shows a present invention electronic device 60 similar to that ofelectronic device 30 shown in FIG. 6, but with an additional dielectriccap layer 62 deposited between the first insulating material layer 38and the second insulating material layer 44. The dielectric cap layer 62can be suitably formed of a material such as silicon oxide, siliconnitride, silicon oxinitride, refractory metal silicon nitride with therefractory metal being Ta, Zr, Hf or W, silicon carbide, siliconcarbo-oxide (SiCO), and their hydrogenated compounds. The additionaldielectric cap layer 62 functions as a diffusion barrier layer forpreventing diffusion of the first conductor layer 40 into the secondinsulating material layer 44 or into the lower layers, especially intolayers 34 and 32.

Another alternate embodiment of the present invention electronic device70 is shown in FIG. 8. In the electronic device 70, two additionaldielectric cap layers 72 and 74 which act as a RIE mask and CMP(chemical mechanical polishing) polish stop layer are used. The firstdielectric cap layer 72 is deposited on top of the first insulatingmaterial (SiCOH) layer 38 and used as a RE mask. The function of thesecond dielectric layer 74 is to provide an end point for the CMPprocess utilized in planarizing the first conductor layer 40. The polishstop layer 74 can be deposited of a suitable dielectric material such assilicon oxide, silicon nitride, silicon oxinitride, refractory metalsilicon nitride with the refractory metal being Ta, Zr, Hf or W, siliconcarbide, silicon carbo-oxide (SiCO), and their hydrogenated compounds.The top surface of the dielectric layer 72 is at the same level as thefirst conductor layer 40. A second dielectric layer 74 can be added ontop of the second insulating material (SiCOH) layer 44 for the samepurposes.

Still another alternate embodiment of the present invention electronicdevice 80 is shown in FIG. 9. In this alternate embodiment, anadditional layer of dielectric 82 is deposited and thus dividing thesecond insulating material layer 44 into two separate layers 84 and 86.The intralevel and interlevel dielectric layer 44 formed of SiCOH, shownin FIG. 8, is therefore divided into an interlayer dielectric layer 84and an intralevel dielectric layer 86 at the boundary between via 92 andinterconnect 94. An additional diffusion barrier layer 96 is furtherdeposited on top of the upper dielectric layer 74. The additionalbenefits provided by this alternate embodiment electronic structure 80is that dielectric layer 82 acts as an RIE etch stop providing superiorinterconnect depth control.

Still other alternate embodiments may include an electronic structurewhich has layers of insulating material as intralevel or interleveldielectrics in a wiring structure that includes a pre-processedsemiconducting substrate which has a first region of metal embedded in afirst layer of insulating material, a first region of conductor embeddedin a second layer of said insulating material wherein the second layerof insulating material is in intimate contact with the first layer ofinsulating material, and the first region of conductor is in electricalcommunication with the first region of metal, a second region ofconductor in electrical communication with the first region of conductorand is embedded in a third layer of insulating material, wherein thethird layer of insulating material is in intimate contact with thesecond layer of insulating material, a first dielectric cap layerbetween the second layer of insulating material and the third layer ofinsulating material, and a second dielectric cap layer on top of thethird layer of insulating material, wherein the first and the seconddielectric cap layers are formed of a material that includes atoms ofSi, C, O and H, or preferably a chemical composition of SiCOH.

Still other alternate embodiments of the present invention include anelectronic structure which has layers of insulating material asintralevel or interlevel dielectrics in a wiring structure that includesa pre-processed semiconducting substrate that has a first region ofmetal embedded in a first layer of insulating material, a first regionof conductor embedded in a second layer of insulating material which isin intimate contact with the first layer of insulating material, thefirst region of conductor is in electrical communication with the firstregion of metal, a second region of conductor that is in electricalcommunication with the first region of conductor and is embedded in athird layer of insulating material, the third layer of insulatingmaterial is in intimate contact with the second layer of insulatingmaterial, and a diffusion barrier layer formed of a material includingatoms of Si, C, O and H deposited on at least one of the second andthird layers of insulating material.

Still other alternate embodiments include an electronic structure whichhas layers of insulating material as intralevel or interleveldielectrics in a wiring structure that includes a pre-processedsemiconducting substrate that has a first region of metal embedded in afirst layer of insulating material, a first region of conductor embeddedin a second layer of insulating material which is intimate contact withthe first layer of insulating material, the first region of conductor isin electrical communication with the first region of metal, a secondregion of conductor in electrical communication with the first region ofconductor and is embedded in a third layer of insulating material, thethird layer of insulating material is in intimate contact with thesecond layer of insulating material, a reactive ion etching (RIE) hardmask/polish stop layer on top of the second layer of insulatingmaterial, and a diffusion barrier layer on top of the RIE hardmask/polish stop layer, wherein the RIE hard mask/polish stop layer andthe diffusion barrier layer are formed of a material including atoms ofSi, C, O and H.

Still other alternate embodiments include an electronic structure whichhas layers of insulating materials as intralevel or interleveldielectrics in a wiring structure that includes a pre-processedsemiconducting substrate that has a first region of metal embedded in afirst layer of insulating material, a first region of conductor embeddedin a second layer of insulating material which is in intimate contactwith the first layer of insulating material, the first region ofconductor is in electrical communication with the first region of metal,a second region of conductor in electrical communication with the firstregion of conductor and is embedded in a third layer of insulatingmaterial, the third layer of insulating material is in intimate contactwith the second layer of insulating material, a first RIE hard mask,polish stop layer on top of the second layer of insulating material, afirst diffusion barrier layer on top of the first RIE hard mask/polishstop layer, a second RIE hard mask/polish stop layer on top of the thirdlayer of insulating material, and a second diffusion barrier layer ontop of the second RIE hard mask/polish stop layer, wherein the RIE hardmask/polish stop layers and the diffusion barrier layers are formed of amaterial including atoms of Si, C, O and H.

Still other alternate embodiments of the present invention includes anelectronic structure that has layers of insulating material asintralevel or interlevel dielectrics in a wiring structure similar tothat described immediately above but further includes a dielectric caplayer which is formed of a material including atoms of Si, C, O and Hsituated between an interlevel dielectric layer and an intraleveldielectric layer.

The present invention novel method and the electronic structures formedby such method have therefore been amply demonstrated in the abovedescriptions and in the appended drawings of FIGS. 1˜9. It should beemphasized that the examples of the present invention electronicstructures shown in FIGS. 6˜9 are merely used as illustrations for thepresent invention novel method which, obviously, can be applied in thefabrication of an infinite number of electronic devices.

While the present invention has been described in an illustrativemanner, it should be understood that the terminology used is intended tobe in a nature of words of description rather than of limitation.

Furthermore, while the present invention has been described in terms ofa preferred and several alternate embodiments, it is to be appreciatedthat those skilled in the art will readily apply these teachings toother possible variations of the inventions.

The embodiment of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A material comprisingSi, C, O and H, said composition having a non-polymeric, covalentlybonded structure comprising Si—C, Si—H, Si—O and C—H bonds and adielectric constant of not more than 3.6.
 2. A material compositionaccording to claim 1, wherein said composition further comprises betweenabout 5 and about 40 atomic percent of Si; between about 5 and about 45atomic percent of C; between 0 and about 50 atomic percent of O; andbetween about 10 and about 55 atomic percent of H.
 3. A materialcomposition according to claim 1, wherein said composition having acovalently bonded three-dimensional network.
 4. A material compositionaccording to claim 1, wherein said composition having a covalentlybonded ring network.
 5. A material composition according to claim 1,wherein said composition being thermally stable to a temperature of atleast 350° C.
 6. A film formed of the material composition according toclaim 1, wherein said film having a thickness of not more than 1.3micrometers and a crack propagation velocity in water of less than 10⁻⁹m/s.
 7. A film according to claim 6, wherein said crack propagationvelocity in water is less than 10⁻¹⁰ m/s.
 8. A material compositionaccording to claim 1, wherein said Si atoms are at least partiallysubmitted by Ge atoms.
 9. A material composition according to claim 1,wherein said composition preferably having a covalently bonded ringnetwork and a dielectric constant of not more than 3.2.
 10. A materialcomposition according to claim 1 further comprising at least one elementselected from the group consisting of F, N, and Ge.
 11. A materialcomposition comprising elements of Si, C and H, said composition havinga non-polymeric covalently bonded structure comprising Si—C, Si—H andC—H bonds and a dielectric constant of not more than 3.6.
 12. A materialcomposition according to claim 11, wherein said composition furthercomprises between about 5 and about 40 atomic percent of Si, betweenabout 5 and about 45 atomic percent of C, and between about 10 and about55 atomic percent of H.
 13. A material composition according to claim11, wherein said composition having a covalently bondedthree-dimensional network.
 14. A material composition according to claim11, wherein said composition having a covalently bonded ring network.15. A material composition according to claim 11, wherein saidcomposition being thermally stable to a temperature of at least 350° C.16. A film formed of the material composition according to claim 11,wherein said film having a thickness of not more than 1.3 micrometersand a crack propagation velocity in water of less than 10⁻⁹ m/s.
 17. Afilm according to claim 16, wherein said crack propagation velocity inwater is less than 10⁻¹⁰ m/s.
 18. A material composition according toclaim 11, wherein said Si atoms are at least partially substituted by Geatoms.
 19. A material composition according to claim 11, wherein saidcomposition preferably having a covalently bonded ring network and adielectric constant of not more than 3.2.
 20. A material compositionaccording to claim 11 further comprising at least one element selectedfrom the group consisting of F, N, and Ge.
 21. A material comprising Si,C, O and H, said composition having a non-polymeric, covalently bondedring network.
 22. A material composition according to claim 21 furthercomprising Si—C, Si—H, Si—O and C—H bonds.
 23. A material compositionaccording to claim 21, wherein said composition further comprisesbetween about 5 and about 40 atomic percent of Si; between about 5 andabout 45 atomic percent of C; between 0 and about 50 atomic percent ofO; and between about 10 and about 55 atomic percent of H.
 24. A materialcomposition according to claim 21, wherein said composition having acovalently bonded three-dimensional network.
 25. A material compositionaccording to claim 21, wherein said composition being thermally stableto a temperature of at least 350° C.
 26. A film formed of the materialcomposition according to claim 21, wherein said film having a thicknessof not more than 1.3 micrometers and a crack propagation velocity inwater of less than 10⁻⁹ m/s.
 27. A film according to claim 26, whereinsaid crack propagation velocity in water is less than 10⁻¹⁰ m/s.
 28. Amaterial composition according to claim 21, wherein said Si atoms are atleast partially submitted by Ge atoms.
 29. A material compositionaccording to claim 21, wherein said composition having a dielectricconstant of not more than 3.6.
 30. A material composition according toclaim 21 further comprising at least one element selected from the groupconsisting of F, N, and Ge.